Burner



Aug. 11, 1931.

BURNER H. A. GEAUQUE A Filed Jan. 15, 1930 (Itt'omegs Patented Aug. 11, 1931 UNITED STATES HARRY A. GEAUQUE, `OF GALESBURG, ILLINOIS BURNER Application filed January 15, 1930. Serial No. 420,897.

My invention relates to burners of the class generally designated Bunsen burners, and

more particularly to gas and air mixing tubes Y for this kind of burner.

Such burners comprise, in general, a gas and air mixing tube, a gas inlet orifice which is arranged axially of the tube, and one or more relatively large valved air inlet ports in the tube. The gas and air enter one end ,10 of the tube, and, in burners heretofore provided, are mixedv to a greater or lesser extent as they pass through the tube. Although burners of this simple construction have been quite well adapted for ordinary uses, they Y 15 havebeen subject to disadvantages resulting from inadequate mixing ofthe gas and air, one of the chief disadvantages being that such burners have exhibited a marked tendf ency to backfire, so that combustion, instead of taking place only at the outlet end of the tube, has at tim-es taken place immediately adjacent the gas inlet orifice. This tend-vv ency is, I believe, fundamentally due to the fact that the gas which enters the tube from aA relatively small orifice at the center of the tube flows through the center ofthe tubeat a lhigh velocity, whereas the'airV entering from the sides of the tube, and through relatively large ports, passes up through the tube ad-l jacentits inner surface at a relatively low velocity. By the time the air and gas have reaohedthe outlet end of the tube, a combustible'mixture has been formed adjacent the inner surface of the tube, and, since this mixture is travelling at a low velocity, it is quite easy for the flame to travel down through the tube along itsinner surface until the gas issuing from the gas nozzle is ignited at that point.

as to cause the gas and air passing through-the f tube to be given a rapid swirling movement and an expansion of the mixture for effecting '59 better mixing of the gas and air and at the I have found that by increasing the veloc` same time deflecting the mixture towards the center of the tube so as topreventthe Slow movement of a combustible mixture along the inner surface of the tube.

vOther objects will become apparent from` the followingv description, the appended claims, and the several views of the invention illustrated in the drawings, in which:

Figure l isa central vertical sectional view of a burner embodying my invention;

Figure 2 is a detail View in front elevation ofl a mixing tube, with parts within shown by dotted lines; Y

Figure 3- is a detail perspective view in elevation of a helix;`

Figure l is a detail view in elevation of an air valve sleeve; and 1 1lIigure 5 is a top plan view of the burner tu e.

In the drawings, therevis shown a burner including a base A, a gasvalve B securedv to thebase, anda burner tube generally designated C mounted on the gas valve.

The base A is Aformedwith acentrally located threaded opening 1 intoV which l'is' screwed an exteriorly kthreaded boss 2 on a gas valve casing 3. The valve casing is formed with a vcentral chambers: which is adapted to receive gas from a nipple 5 threadably connected to the body 3, and to discharge gas upwardly into the tube C through a gas orifice 6 locatedfaxially of the tube.-

The boss 2 on the valve body is formed with an internally threaded opening 7 into which is screwed a threaded valve stem 8,

as at 11, anda helix 12 located within the barrel l0 between the gas inlet orifice 6 and the upper or outlet end of the barrel. The barrel is also provided with air inlet ports 'I3-13 i and with a rotatable sleeve 14 mounted on the outside of the barrel and having 'openings -15 adapted to register with the openings 13-13 in the barrel forcontrollin the ow of air into the barrel.

In accordance with my invention, the helix 12 is so constructed that its pitch, or in other words the distance between adjacent turns of the helix, increases from the inlet end of the tube towards the outlet end thereof. Because of this increasing pitch of the helix, the air entering the tube and travelling close to the inner surface of the tube and upwardly towards the outlet end will be given a rapid swirling motion and also an expansion of the air which promotes better mixing of the air and gas; and, at the same time, the air is deflected inwardly towards the center of the tube which prevents the slow movement of a combustible mixture along the inner surface Aof the tube and thus lessens the tendency for the flame to backfire. The helix is preferably of gradually increasing pitch and thus produces the same effect as a Vent-uri tube kin that the gas is graduallyexpanded as it flows around the successive turns of the helix and up through the tube. It is evident that any particular volume of gas, say for instance that contained between the second'and third turns of the helix at a given`instant,-will, uponflowing into the space between the third andfourth turns thereof, tend to occupy a larger volume, since the third and` fourth turns are :spaced farther apart than the --second and third turns. This of course results inV an expansion of that volume of gas and aconsequent more perfect mixing thereof.:l lVhen gas flows towardV the outlet end ofthe tube J and thereby successively passes around the several turns of the helix, it'will'be still further expanded. This comb-ined swirling and simultaneous expansion of the .gas and air progressively in a strict sense.

mixtureV has been found to mix the air and gas more efficientlythan was heretofore possible and to also prevent backfiring of the flame. c Y

To the attainment ofthe .obj ects of the invention, it is necessary that the' helix-be of varying pitch, and preferably the pitch in-A creases from the inner end ofthe tube to the outer end thereof, although it is not neces-` sary that the pitch vary uniformly or even :'Ihus, the first and'second turns may be spaced the same distance apart as the second and third turns,

Ybut the turns adjacent the inner end :of thetube should, in general, be closer together than the turns at the 'outer end of thev tube. T he helix 12 is illustrated as comprising a spirally wound springwhich is positioned in the barrel 10 and maintained therein by the frictional contact of the several turns of the spring with the inner surface of thebarrel. Obviously, the helix may, if desired, be

formed integrally Vwithfthe barrel; but theY form illustrated is believed to be most suit-V n able in that it is adapted to be easily applied l to a tube of standardl form.

For still better mixing of the air and-gas emerging from the o utletendof the tube, I

employ a reticulated baflie 16 which includes a rim 17 adapted to be frictionally held within the upper end of the barrel and a screen 18 secured to the rim.

Experience has demonstrated that a baille of this kind when used in connection with a burned vtube provided with a helix of varying pitch cooperates with the tube in providing a flame o f great uniformity and at the same time eliminates the heretofore existent tendency for the flame to backfire.

I claim as my invention:

1. A mixing tube for a burner, comprising a barrel having an inlet end and an outlet end, and a helix in the barrel and arranged coa-xiallv therewith, the pitch of said helix Y increasing from the inlet end of said tube to Y and means in said barrel for expanding gas passing fromthe inlet end to the outlet end thereof in the manner of a Venturi tube,com prising a spirallywound element the turns of which are arranged in contacting relation with the inner surface of the barrel, the distance between adjacent turns of said elementI` increasing progressively from the inlet end 4to .the outlet end of the barrel. c

4. In a burner mixing tube, the comb-ination with a barrel havingv gas inlet and outlet ends, of aspirally wound spring posiz;l tionedl within-.said barrel and maintained therein by frictionalcontact of the spring with the inner surface ofthe barrel, the pitch of said spring increasing from the inlet end to the outlet endof said barrel. f 5. In a burner, the combination with a gas and air mixing tube including a barrel having intake and outlet ends, of a gas inlet openand the outlet endof the barrel, tlievpitch of;u said helix increasing from said air port to said outlet end. Y

6. In a burner, the combination witha gas and air mixingtubre including a barrelhaving intake and outlet ends, of aV gas inletN opening at the intake endof the barrel and disposed substantially at `the axis thereof.

an air port in said barrel adjacent the intake end thereof, and a helix mounted in contactingrelation withthe inner surfaceof the bare..

ing atthe intake vend of the barrel and disposed substantially at the axis thereof, an;

rel and disposed between said air port and the outlet end of the barrel, the pitch of said helix gradually increasing from said air port to said outlet end, and a screen at the outlet end of said barrel.

7. In a burner, the combination with a gas and air mixing tube including a barrel having intake and outlet ends, of a gas inlet opening at the intake end of the barrel and disposed substantially at the aXis thereof, and an air port in said barrel adjacent said gas inlet opening, the inner surface of said barrel being provided With a spiral of gradually increasing pitch from the intake end of said barrel to the outlet end thereof, the

minimum pitch of said spiral being adjacent said gas inlet opening and said air port, whereby gas and air passing from the inlet to the outlet end of the barrel will be expanded as in a Venturi tube.

In testimony whereof, I have hereunto subscribed my name.

HARRY A. GEAUQUE. 

